"Now this I say and testify in the Lord, that you must no longer walk as the Gentiles do, in the futility of their minds. They are darkened in their understanding, alienated from the life of God because of the ignorance that is in them, due to their hardness of heart. They have become callous and have given themselves up to sensuality, greedy to practice every kind of impurity. But that is not the way you learned Christ!" (Ephesians 4:17-20 ESV)
"...and my speech and my message were not in plausible words of wisdom, but in demonstration of the Spirit and of power, that your faith might not rest in the wisdom of men but in the power of God." (1 Corinthians 2:4-5 ESV)
"The great philosopher has no advantage over the pagan in this matter of the gospel. Until both of them come under the influence and the power of the Holy Spirit of God, neither will see it. But thank God, when the Holy Spirit comes upon both, both will see it; not only the philosopher, not only the pagan, but both together! ... It is not a matter of intellectual ability, be it small or great; it is a matter of this power of vision; man has lost it, his understanding is darkened, and that is the effect of the Fall."
"Do we recognize the cause of the trouble, that it is this appalling darkness that has come over and enshrouded the understanding? And even though we do everything we can, it will avail nothing. There is only one thing that can move the mist, and take away the pall, and that is the gale of the Spirit. We have tried almost everything else, have we not? We have organized and arranged and used means and methods that even we ourselves have felt to be doubtful..."
"No human agency can do it. But the Spirit can -- 'in demonstration of the Spirit and of power'... We are only Christians because the Spirit of God has opened our blind eyes, and has taken away the darkness."
"Men 'walk in the vanity of their mind, having the understanding darkened'. Poor, benighted fools, despite their sophistication and cleverness, their arguments and disputes on the wireless [radio] and the television, and their articles and their books! How brilliant! But it is the brilliance of a bubble! There is nothing in it. And their blindness is the result of darkness. Have compassion upon them. Do not be content with denouncing them, pray for them. Above all, pray that the Spirit of God may come in such power that their darkness may be removed and their eyes opened."
~ Martyn Lloyd-Jones, Darkness and Light: An Exposition of Ephesians 4:17--5:17 (Baker Books, 1982), pp. 48-51.
Hear the sermon "Darkness and Light" here.